Emotional expression and gaze direction are important signals of the internal states and intentions of others and are critical to the human social experience. {These core abilities interact with other nonverbal forms of communication to form the basis of complex social cognitive processes such as theory of mind (Baron- Cohen, 1995).} It is not surprising that the disruption of these processes is associated with socio-affective disorders such as schizophrenia and autism. Neurophysiological evidence in healthy subjects suggests that expression and gaze are processed, at least in part, by the same brain areas. Behavioral evidence corroborates this, and suggests that the timing of these processes is crucial in whether or not they interact. Timing, in turn, is affected by how easily these dimensions can be discriminated. {Event-related potentials (ERPs) can provide important confirmation of these hypotheses regarding gaze and expression processing interactions, providing a more thorough understanding of the biological basis of social intelligence.} An understanding of gaze and emotion processing in healthy adults provides a basis for delineating how these processes might be disrupted by development, disease or injury. Using ERPs, expression and gaze perception in healthy adults will be examined with the Garner interference paradigm. This paradigm provides an index of processing interdependence by determining the extent to which perceivers can selectively attend to one stimulus dimension (e.g. emotion) while ignoring the other (e.g. gaze). In Experiment 1, gaze and expression interactions will be examined with unambiguous fearful and angry expressions and direct and averted gaze. {Behavioral evidence has demonstrated that when expressions are easily discriminated, subjects are able to perform expression judgments without interference from gaze, but unable to make gaze judgments without interference from expression.} Expression was judged more quickly, suggesting that this asymmetric interference arose because expression was processed before gaze could interfere. {ERPs could provide corroborating evidence regarding the timing of these processes.} In Experiment 2, the difficulty of emotion discrimination will be increased by using more subtle facial expressions. Graham & LaBar have shown that when expression was more difficult to discriminate, gaze interfered with emotion judgments and vice versa. This suggests that expression and gaze interactions are modulated by discriminability: whereas expression generally interferes with gaze judgments, gaze modulates expression processing only when emotion discrimination is difficult.{ ERPs are uniquely poised to examine such a speed-of-processing account of these interactions, providing important confirmation about the timing of these interactions in the healthy adult brain.} A great deal of information about others' thoughts and feelings can be determined from emotional expressions and direction of gaze. This research is designed to examine the electrical activity of the brain when individuals view emotional and gazing faces. The goal of this project is to provide a better understanding of the biological basis of social intelligence, a skill that critical to healthy human function. [unreadable] [unreadable] [unreadable]